The specific aims of this core have been modified to better serve the needs of the various projects included in the modified program. Our Aims are: 1) To apply standardized criteria for diagnostic classification of ovarian tumors from patients enrolled in investigational protocols; 2)To provide resources for immunohistochemical evaluation of ovarian carcinomas and the creation ovarian carcinoma tissue microarrays to facilitate the identification of potential therapeutically and diagnsostically relevant targets in human and mouse tissue using immunohistochemistry; 3) To develop and validate methods to characterize eligibility for and responses to targeted therapy; 4) To support the tumor tissue bank as a resource of project investigators. Since the last application, we have added a second Gynecologic Pathologist, Dr Carmen Tornos, as a participant in the program. We have moved all of the mouse pathology activities into this core. The use of our expertise in immunohistochemistry will become increasingly important as we investigate both cell surface targets and cellular signal transduction molecules in the new application. The use of tissue microarrays will allow us to develop efficient, high throughput analysis of dozens of ovarian cancer samples as we seek to validate new targets in large panels of ovarian cancer samples. The analysis of secondary debulkings and core biopsies of recurrent cancers will also allow us to ascertain the efficacy of immune targeting to eliminate specific surface epitopes from the cancer cell population.